SAED Patterns of Single Crystal, Polycrystalline and Amorphous Samples

r1 r2200

Electron Diffraction

Specimen foil

[hkl] SAED pattern

L -camera lengthr -distance between T and D spots1/d -reciprocal of interplanar distance(Å-1)SAED –selected area electron diffraction

Geometry fore-diffraction

Bragg’s Law: = 2dsin

=0.037Å (at 100kV)=0.26o if d=4Å

= 2dr/L=sin2as 0r/L = 2

r/L = /d or

r = Lx1

Reciprocal lattice

Ewald’s Sphere

Ewaldcircle

incident beam

diffracted beam

Ewald’s sphere is built for interpreting diffraction

CG-C0=0G or kd-ki=g Laue equation

lkl=1/

Wherever a reciprocal lattice point touches the circle, e.g., at G, Bragg's Law is obeyed and a diffracted beam will occur. At H, no diffraction.

Convergent Beam Electron Diffraction (CBED)

CBED uses a conver-gent beam of elec-trons to limit area of specimen which con-tributes to diffractionpattern.Each spot in SAED thenbecomes a disc withinwhich variations inintensity can be seen.CBED patterns containa wealth of informationabout symmetry andthickness of specimen.Big advantage of CBEDis that the informationis generated from smallregions beyond reachof other techniques.

SAED vs CBED

spots disks

sample

Parallel beam Convergent beam

T D T D

Convergence angle

objective

SAED CBED

Spatial resolution >0.5m

Spatial resolutionbeam size

CBED-example 1

CBED-example 2

HOLZ - High Order Laue Zone

Applications of CBED

•Phase identification•Symmetry determination-point and

space group•Phase fingerprinting•Thickness measurement•Strain and lattice parameter measurement •Structure factor determination

Symmetry Deviations

Phase Identification in BaAl2Si2O8

200oC 400oC 800oC

<0001>

Hexagonal Orthorhombic Hexagonal

6mm 2mm 6mm

Phase Fingerprinting By CBED

[001] CBEDpatterns of anantiferroelectricPbZrO3 singlecrystal specimenat (a) 20oC, (b)280oC, (c)220oC.(d) [001] CBEDpattern of a rhombohedral ferroelectric Pb(ZrTi)O3 Specimen at 20oC.

Orthorhombic AFE Cubic PE

Rhombohedral FE Rhombohedral FE

Symmetry and Lattice Parameter Determination

CBED-HOLZ

Experimental simulated

Latticeparameters

SAED Patterns of Single Crystal, Polycrystalline and Amorphous Samples

Documents

Black Ge Based on Crystalline/Amorphous Core/Shell ...nanophotonics.eecs.berkeley.edu/Publications... · amorphous outer shell, polycrystalline inner shell, and an ultrathin single

Introductionto Distributed Generation Eugeniusz Rosołowski ...solar radiation into direct current electricity. • Materials presently used for PVs include amorphous silicon, polycrystalline

SAED Recertification

Chapter 3Chapter 3 Highlights: 1. 3 types of materials- amorphous, crystalline, and polycrystalline. 2. Understand the meaning of crystallinity, which refers to a regular lattice based

SAED Refresher Training

Cells, Modules, & Arrays. Types of PV Cells/Products Single Crystal Multi or Polycrystalline Thin Film /Amorphous Silicon

SAED Digital Standard Cell Library_Rev1!4!20

Mohamed Saed

Organic 2 -chapter 16- Dr.Naem al saed -

Crystallography OverviewCrystallography Overvie · This unit will discusses three topics of crystallography: The types of solid matter (amorphous, polycrystalline and crystalline)

JSMSx-ray.jsms.jp/memo/ES1.pdf · EN 13925-1, Non-destructive testing - X-ray diffraction from polycrystalline and amorphous material - Part 1: General principles. EN 13925-2, Non-destructive

Polycrystalline diamond compact

Dielectric permittivity and AC conductivity in ...The dielectric permittivity and AC conductivity of polycrystalline and amorphous C60 samples were measured at temperatures between

C LUSTERING (Segmentation) Saed Sayad 1

Introduction to Solids. 3 Classes of Solids Amorphous – No long range order Polycrystalline – Order within grains Single Crystal – Regular, repeated pattern

Optical and electrical properties of polycrystalline and amorphous … · with transition metals (TMs), such as Ti, has turned out to di-minish premature fatigue issues associated

Electron Diffraction - ICDD...comprehensive materials database that is the key source of ... Figure 1: Electron diffraction simulation of (a) an amorphous, (b) a polycrystalline, or

Fundamentals - International Centre for Diffraction Data...“X‐Ray Diffraction Procedures for Polycrystalline and Amorphous Materials”, Harold P. Klug and L. R. Alexander, Wiley‐Interscience,

Independent degree project - first cycle1168982/FULLTEXT01.pdfKeywords: Solar cell, Photovoltaics, Amorphous silicon, Monocrystalline silicon, Polycrystalline silicon, Cupper indium

1 Fibers for Ceramic Matrix Composites - Wiley-VCH · PDF file2 1 Fibers for Ceramic Matrix Composites either polycrystalline, partially crystalline, or amorphous. However, the expression